Industrial Pretreatment Program

Publicly owned treatment works (POTWs) collect wastewater from homes, commercial buildings, and industrial facilities and transport it via a series of pipes, known as a collection system, to the wastewater treatment plant (WWTP). The WWTP removes pollutants from wastewater so it can be discharged safely into the Fore River, and ultimately Casco Bay.

Generally, WWTPs are designed to treat domestic sewage only. However, they also receive wastewater from industrial (non-domestic) users. In accordance with state and federal laws, the City has established uniform industrial pretreatment standards to ensure the safe and efficient operation of our wastewater treatment system. More specifically, these standards are intended to prevent the discharge of pollutants from non-domestic sources into the sewer system that could:

  • interfere with the operation of the wastewater treatment system;
  • cause the wastewater treatment plant to violate its effluent discharge permit;
  • contaminate the sludge;
  • pass through the system into receiving waters or the atmosphere without adequate treatment;
  • pose a health threat to sewer workers; or
  • be otherwise incompatible with the system.

Visit Chapter 29 of the City’s ordinance for detailed information on our Industrial Pretreatment Program. Also see Chapter 22 for related information on the City’s sewer system construction and wastewater disposal requirements.